Investigation for influence of space charge accumulation in motor winding coating material on partial discharge inception voltage

It is said that a space charge accumulation in an insulating material for motor windings decreases the partial discharge inception voltage (PDIV). Therefore, the space charge distribution measurement is important in the insulating material under square wave voltage, which is applied to an actual motor. In this study, we tried to understand the relationship between the space charge accumulation and the change of PDIV by comparing the experimental results obtained using PEA (pulsed electroacoustic) method and PDIV testing systems.